Spool for fastener strips and method of winding fastener strips

ABSTRACT

A spool for a fastener strip includes a cylinder comprising a substantially U-shaped recess or protrusion for accommodating a turn in the fastener strip such that an upstream portion and a downstream portion of the fastener strip can point in the same direction. The recess or protrusion allows the strip to be wound onto the spool in such a manner that when the strip is unwound, there is a sufficiently long lead of fastener strip to allow an operator to replace the emptied spool with a new spool and to splice an upstream end of the strip from the emptied spool with a downstream end of the strip from the new spool.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.60/684,519, filed on May 26, 2005; the entire content of which is herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention generally relates to a spool for fastener stripsand a method of winding a fastener strip.

BACKGROUND

Typically, reclosable bags or pouches are made by joining a pre-madefastener strip or zipper strip with a web of packaging material. Thefastener strip is usually flat and wide. The fastener strip is commonlysold and fed in a production line on a spool or roll. When the fastenerstrip on the spool runs out, the old spool is replaced with a new spool,and ends of the fastener strip from the two spools are spliced together.

However, a drawback occurs when the fastener strip on the spool runsout. In particular, the production line needs to be stopped for thespools to be replaced and the ends of the fastener strip from the oldspool and the new spool to be spliced together. This often causes delayand/or disruption in the bag manufacturing process as well as delayand/or disruption in any integrated downstream process steps.

Therefore, there is a need in the art to provide a spool for a fastenerstrip and a method of winding that strip so as to allow the spool to bereplaced and the two ends of the fastener strips to be spliced togetherwithout stopping the process line.

SUMMARY

An exemplary spool for fastener strips comprises a cylinder on which towind a fastener strip. The cylinder includes a substantially U-shapedrecess for accommodating a turn in the fastener strip such that anupstream portion and a downstream portion of the fastener strip canpoint in the same direction.

Another exemplary spool for fastener strips comprises a cylinder onwhich to wind a fastener strip. The cylinder includes a substantiallyU-shaped protrusion for accommodating a turn in the fastener strip suchthat an upstream portion and a downstream portion of the fastener stripcan point in the same direction.

An exemplary method of winding a fastener strip comprises providing aspool comprising a substantially U-shaped recess and winding a fastenerstrip around the substantially U-shaped recess such that an upstreamportion and a downstream portion of the fastener strip point in the samedirection.

Another exemplary method of winding a fastener strip comprises providinga spool comprising a substantially U-shaped protrusion and winding afastener strip around the substantially U-shaped protrusion such that anupstream portion and a downstream portion of the fastener strip point inthe same direction.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings provide visual representations which will beused to more fully describe the representative embodiments disclosedherein and can be used by those skilled in the art to better understandthem and their inherent advantages. In these drawings, like referencenumerals identify corresponding elements and:

FIG. 1A shows a side view of an-exemplary embodiment of the spool of thepresent invention.

FIG. 1B shows a front elevational view of the exemplary embodiment ofFIG. 1A.

FIG. 2A shows a side view of another exemplary embodiment of the presentinvention.

FIG. 2B shows a front elevational view of the exemplary embodiment ofFIG. 2B.

FIG. 3 shows a perspective view of the spool of the present inventionwith a fastener strip attached.

FIG. 4 shows another perspective view of the spool of the presentinvention with a fastener strip attached.

FIG. 5 shows a perspective view of the correlation between the upstreamend of a fastener strip of an emptied spool and the downstream end of afastener strip of a new spool to be spliced each other.

DETAILED DESCRIPTION

The spool according to the present invention allows a fastener strip tobe wound thereon in such a way that a processing line need not bestopped when the spool runs out of fastener strip. In particular, thespool has a cylinder on which the fastener strip is wound. The cylinderis provided with a recess or a protrusion on its circumferential surfaceto accommodate a U-turn in the fastener strip when the strip is woundonto the spool. The recess or protrusion should have a size and shapesuch that the strip can rest in or on the recess or protrusion and thatadditional fastener strip can be wound around and/or on top of therecess or protrusion without permanently deforming the strip in or onthe recess or protrusion.

Preferably, the recess or protrusion has a substantially U shape. Theterm “substantially U shape” or “substantially U-shaped” is used hereinto include shapes that can accommodate a change in direction of thefastener strip. Such shapes include semi-circles, semi-ovals, V shapes,and U shapes.

Preferably, the open end of the substantially U-shaped recess orprotrusion is pointed in the machine direction or the direction in whichthe fastener strip is unwound.

When a fastener strip is placed in the recess or around the protrusion,and wound onto the cylinder of the spool, a sufficient amount of stripshould be provided on the upstream end such that an operator can havesufficient time to replace the spent spool with a new spool and tosplice one end of the strip from the spent spool with a downstream endof the strip from the new spool, without stopping the production line inwhich the strip is used.

FIGS. 1A and 1B show an exemplary spool 10 according to the presentinvention. The spool 10 has a cylinder 12 having a circumferentialsurface 14 onto which a fastener strip can be wound. According to theexemplary embodiment, the outer surface 14 of the cylinder 12 includesrecess 30 for receiving a portion of the fastener strip therein. Therecess 30 is substantially U-shaped.

The recess 30 allows for the fastener strip to be wound on top of the Uturn in the strip without permanently deforming it. Preferably, therecess 30 is deepest and narrowest at its center portion 32, andshallows and widens towards the sides 34 (not shown). At the deepestpoint, the fastener strip is substantially perpendicular to the outersurface of the cylinder 12, and mostly or completely held within therecess 30. The width of the recess 30 at the center portion 32 should beat least equal to the thickness of the fastener strip so that the stripcan fit into and fall easily out of the recess 30 when the spool isunwound. As the fastener strip moves to the sides 34 as shown in FIGS. 3and 4, it becomes substantially flat so that it can be wound onto thecylinder 12.

Preferably, the distance L between the ends 36 of the recess is lessthan or equal to the width W of the cylinder 12 minus two times thewidth of the fastener strip. In addition, the radius of curvature R ofthe recess should be sufficiently large so that the fastener strip doesnot become permanently deformed when it is bent to conform to the Ushape.

FIGS. 2A and 2B show another exemplary spool 50 according to the presentinvention. The spool 50 has a cylinder 52 having a circumferentialsurface 54 onto which a fastener strip can be wound. According to theexemplary embodiment, the outer surface 54 of the cylinder 52 includes aprotrusion 56 for supporting a portion of the fastener strip thereon.The protrusion 56 is substantially U-shaped.

The protrusion 56 allows for the fastener strip to be wound on top ofthe U turn in the strip without permanently deforming it. Preferably,the protrusion is highest at its center 72, and tapers down towards thesides 74 (not shown). At the highest point, the fastener strip issubstantially perpendicular to the outer surface of the cylinder 52, andthe height of the center 72 is about the width of the fastener strip. Asthe fastener strip moves to the sides 74 as shown in FIGS. 3 and 4, itbecomes substantially flat so that it can be wound onto the cylinder 52.

Preferably, the distance L between the ends 76 of the protrusion is lessthan or equal to the width W of the cylinder 52 minus two times thewidth of the fastener strip. In addition, the radius of curvature R ofthe protrusion should be sufficiently large so that the fastener stripdoes not become permanently deformed when it is bent to conform to the Ushape.

FIGS. 3 and 4 depict a method of winding the fastener strip according tothe invention. For illustration purposes, a fastener strip 20 is shownwith the spool 10 from FIGS. 1A and 1B. In FIG. 3, the fastener strip 20is placed or wound in the recess (not shown) of the spool 10 such thatan upstream end 22 and a downstream end 24 of the fastener strip 20 canpoint in the same direction. The downstream end 24 of the fastener stripis rolled onto the cylinder 12 in the normal fashion as shown in FIG. 4.The upstream end 22 is provided with a length Ls of the strip to bewound onto the cylinder 12. This length of strip should be sufficientlylong in order to provide an operator with enough time to exchange theemptied spool 10 with a new spool 10′ as depicted in FIG. 5 and tosplice the downstream end 24′ of the new spool 10′ with an upstream end22 of the emptied spool 10.

The fastener strip of the present invention is of the type used forreclosable bags or pouches. The fastener strip may be a zipper-typefastener, or may be a press-to-close device. However, it should beunderstood that the present invention may apply to other types offastener strips or securing devices for packages that are applied in aprocess line.

The presently disclosed embodiments are considered in all respects to beillustrative and not restrictive. The scope is indicated by the appendedclaims, rather than the foregoing description, and all changes that comewithin the meaning and range of equivalents thereof are intended to beembraced.

1. A spool for holding a fastener strip, comprising: a cylinder on whichto wind a fastener strip, said cylinder comprising a substantiallyU-shaped recess for accommodating a turn in said fastener strip suchthat an upstream portion and a downstream portion of said fastener stripcan point in the same direction.
 2. The spool of claim 1, wherein atleast a portion of said recess has a depth at least equal to the widthof said fastener strip.
 3. The spool of claim 1, wherein said recess hasa radius of curvature at least equal to the radius of curvature thatsaid fastener strip can be bent without permanently deforming thefastener strip.
 4. A spool for holding a fastener strip, comprising: acylinder on which to wind a fastener strip, said cylinder comprising asubstantially U-shaped protrusion for accommodating a turn in saidfastener strip such that an upstream portion and a downstream portion ofsaid fastener strip can point in the same direction.
 5. The spool ofclaim 4, wherein at least a portion of said protrusion has a height atleast equal to the width of said fastener strip.
 6. The spool of claim4, wherein said protrusion has a radius of curvature at least equal tothe radius of curvature that said fastener strip can be bent withoutpermanently deforming the fastener strip.
 7. A method of winding afastener strip, comprising: providing a spool according to claim 1;winding a fastener strip around the substantially U-shaped recess suchthat an upstream portion and a downstream portion of said fastener strippoint in the same direction.
 8. The method of claim 7, wherein theupstream portion of said fastener strip is sufficiently long to allow anoperator to replace a spool depleted in fastener strip with a new spooland to splice an upstream end of the fastener strip from the depletedspool with a downstream end of a fastener strip from the new spoolwithout stopping a production line employing said fastener strip.
 9. Amethod of winding a fastener strip, comprising: providing a spoolaccording to claim 4; winding said fastener strip around thesubstantially U-shaped protrusion such that an upstream portion and adownstream portion of said fastener strip point in the same direction.10. The method of claim 9, wherein the upstream portion of said fastenerstrip is sufficiently long to allow an operator to replace a spooldepleted in fastener strip with a new spool and to splice an upstreamend of the fastener strip from the depleted spool with a downstream endof a fastener strip from the new spool without stopping a productionline employing said fastener strip.